Protective refractory member

ABSTRACT

A protective refractory member for protecting heat absorptive elongated elements comprising a hollow refractory element into which is solidly embedded a reticulated metal structure. A series of spaced pluglike openings extend through the refractory element so that the reticulated metal structure, which is substantially adjacent the heat absorptive elongated element can be welded thereto to serve as the sole means of support for the refractory member.

United States Patent Brungraber et al.

{ 51 Mar. 7, 1972 [54] PROTECTIVE REFRACTORY MEMBER [72] lnventors: Louis E. Brungraber, Mt. Lebanon;

Walter Rudin, Whitehall, both of Pa.

[73] Assignee: Bloom Engineering Company, Inc., Pittsburgh, Pa.

[22] Filed: June 1, 1970 [21] Appl. No.: 41,791

[52] US. Cl. ..263/6 B [51] Int. Cl ..F27d 3/02 [58] fieldolSearch ,.263/6,6B; 138/142, 147, 148, 138/149 [56] References Cited UNITED STATES PATENTS 2,693,352 11/1954 Bloom ..263/6 B Balaz et a1. ..263/6 B Primary Examiner-Charles J. Myhre Attorney-Webb, Burden, Robinson & Webb ABSTRACT A protective refractory member for protecting heat absorptive elongated elements comprising a hollow refractory element into which is solidly embedded a reticulated metal structure. A series of spaced pluglike openings extend through the refractory element so that the reticulated metal structure, which is substantially adjacent the heat absorptive elongated element can be welded thereto to serve as the sole means of support for the refractory member.

5Claims,3DrawingFigures Doherty et al ..263/6 B X FATENTEUHAR 7 I972 3,647, 194

IN VENTORS. Louis E. Brungrabe r Walter Rad/n i w M THE/R ATTORNEYS PROTECTIVE REFRACTORY MEMBER This invention relates to furnace insulation systems and, more particularly, to a protective refractory member for protecting heat absorptive elongated elements, such as support members and pipe in a metallurgical furnace.

Various furnace insulation systems have been installed in modern day furnaces to protect the metal structures contained therein, such as the skid pipe, crossover pipe, riser pipe and other support members. These pipe are hollow and are watercooled, thereby making them very heat absorptive. These pipe must be protected to minimize the heat losses of the furnace. Further, these insulation systems are subject to repetitive vibrations, scale buildup and occasional damaging blows from workpieces or chunks of metal or scale. Therefore, the proper anchoring of such an insulation system is an important criteria. One such furnace insulation system is described and claimed in US. Pat. No. 2,693,352, F. S. Bloom, patentee. The Bloom furnace insulation system comprises two refractory sections, each having interconnected reticulated metal mesh embedded therein so that when the two sections are joined about a furnace pipe, they are securely anchored (e.g., by welding) to the pipe at the exposed metal mesh at the juncture of the sections. Thereafter, the juncture is filled in to completely cover the exposed mesh at the welds, thereby completing the installation. The Bloom furnace insulation system has been very successful in protecting skid pipe, as well as the crossover and riser pipes in a furnace. The installation of the Bloom insulation system does necessitate removing all the metal workpieces from the skid pipe, as well as cooling down the furnaces to permit entry.

Our invention provides an improvement on the basic Bloom furnace insulation system to permit the protective refractory to be installed without removing the metal workpieces from the skid pipe and without sacrificing the effective life of the installation. This improvement is a considerable time saver, thereby permitting the processes of the furnace to be continued after a minimum downtime. In addition, our invention eliminates the extended mortar joints and further eliminates pins or metal mesh extending out of the refractory which served as means of anchoring the refractory members to the furnace pipes in certain embodiments of the Bloom insulation system.

Our invention provides a refractory member to protect the heat absorptive elongated elements in a furnace. The refractory member has an elongated hollow element into which is solidly embedded a reticulated metal structure. The reticulated metal structure, generally a high temperature alloy wire mesh, is positioned about the hollow portion to be substantially adjacent the skid pipe. A plurality of pluglike openings extend through the refractory member, thereby permitting this refractory member to be anchored to the skid pipe, such as by welding the wire mesh to the skid pipe through the openings. This anchoring is the sole means of support between the refractory member and the skid pipe.

In the accompanying drawings, we have shown one preferred embodiment of our invention in which:

FIG. 1 is an isometric of an insulated skid pipe;

FIG. 2 is a section through lines II-II of FIG. 1; and,

FIG. 3 is an isometric showing the protective refractory member.

A multizone reheat furnace, which heats steel slabs to proper temperatures prior to hot rolling, is a typical example of the environment in which our protective refractory members are employed. Another environment is open hearth furnaces, and it will be appreciated that many other similar environments require such insulation systems. A multizone reheat furnace has a network of pipes which are water-cooled and which serve as supports for the slabs being processed through the furnace. The pipe which actually supports the slab is referred to as a skid pipe and because of the normal wear of metal to metal contact, a wear bar is secured to the top of the pipe so that the effective wall thickness of the pipe is not reduced and the wear bar takes the metal loss. In addition, crossover pipes and riser pipes are employed in the structural network to facilitate the cooling of all members involved. A typical section of skid pipe 10 is shown in FIG. 1 having a wear bar 11 welded thereto. The refractory member I2 is the shape of a hollow cylinder having a flat segmented section 13 which terminates just below the top ofthe skid pipe 10 so that there is an open area 14 in the top of the refractory member 12 to accommodate the wear bar 11 which is welded to the top of the skid pipe 10, see FIG. 3.

The refractory member 12 has an interconnected wire mesh 15 solidly embedded therein and positioned about the hollow portion 16 of the refractory member 12. This mesh 15 is substantially at the inner surface of the refractory member 12 so that at least portions are immediately adjacent the outer diameter of the skid pipe 10 when positioned in place. The wire mesh can be in many forms of a reticulated metal structure, and the particular form is not critical for purposes of defining the subject invention. For ease of presentation, the wire mesh 15 is shown exposed at the ends of the refractory member 12, but it will be appreciated by those skilled in the art that the wire mesh can be completely covered, excepting the portions to be attached to the skid pipe through the pluglike openings.

A plurality of pluglike openings 18 extend through the refractory member 12, thereby exposing those portions of the wire mesh 15 immediately adjacent the skid pipe 10. The refractory member 12 is anchored to the skid pipe 10 by welding the wire mesh 15 to the skid pipe 10 through the pluglike openings 18.

The refractory member 12 actually is constructed in two parts which are connected along the bottom surface of the refractory. The loops of the wire mesh of the respective parts are interwoven and a pin or wire is threaded therethrough to form a hingelike connection. The edges of the two respective parts are chamfered to permit swinging movement about the hingelike connection. The refractory member 12 is then fitted about the skid pipe by opening the two parts and placing the refractory member over the pipe. The two parts are then closed about the pipe and the hingelike connection is completely grouted. This form of connection, shown as 20 in FIGS. l-3, is known and does not form a part of this invention.

Since the attachments of the wire mesh 15 to the skid pipe 10, through these pluglike openings 18, represent the sole means of securing the refractory member 12 to the skid pipe, a plurality of pluglike openings should be provided. It has been found that a secure anchoring can be achieved by positioning the pluglike openings 18 on either side of the horizontal center line, see FIG. 2, and by offsetting the plugged openings 18 from each other and from a vertical plane, see FIG. 3.

Of course, the length of the refractory member and its particular application will dictate the exact number of pluglike openings necessary. It has been found that refractory members of l-foot lengths and for 4-inch-round skid pipe, require a total of eight pluglike openings to insure good performance. Each of these pluglike openings was positioned three-quarter inch from the horizontal centerline and were staggered so that no two pluglike openings on opposite sides of the horizontal centerline were in the same vertical plane.

After the refractory member 12 has been anchored to the skid pipe 10, the pluglike openings 18 are filled in by a refractory mix to completely cover the exposed wire mesh 15 and complete the installation. The refractory member 12 has been shown cylindrical since most standard skid pipes are of that shape. However, the refractory can be cast to any desired shape, for example, oval shaped when an oval skid pipe is employed. In addition, where metal supports are being protected, the refractory can be in the form of a square rectangle, etc.

Because the refractory member is anchored to the skid pipe through the plug-type holes 18, there is no need to weld along the area of the segmented section 13. Because of this, the slabs do not have to be removed from the wear bar 11 and the refractory member 12 may merely be fitted in place. This represents about an 8 hour savings in time for a standard 5 zone reheat hot mill furnace.

An experimental installation of our invention was conducted in a hot mill reheat furnace of a large steel company. One skid pipe was covered with some 69% feet of our subject protective refractory, and five skid pipe were covered with a normal furnace insulation system, as shown in the Bloom US. Pat. No. 2,693,352. The pluglike openings were substantially frustoconical shaped. After 5 months operation, the experimental refractory had the same amount of wear as the standard refractory on the control skid pipe, and held up at least as good with respect to being anchored to the skid pipe. This indicates that anchoring the refractory member 12 to the skid pipe was at least as efficient as the methods employed heretofore. At the same time the experimental installation was routinely installed and, of course, it can be installed without removing the steel slabs from the furnace. In addition, the extended mortar joints were eliminated and there were no pins or mesh extending out of the refractory to contend with.

We claim:

1. in a protective refractory member for protecting heat absorptive elongated elements in a furnace and having two connected integral parts forming a refractory elongated hollow element and an interconnected reticulated metal structure solidly embedded within said hollow element and positioned about and adjacent the'hollow portion so as to be substantially adjacent said heat absorptive elongated element, the improvement comprising a plurality of spaced pluglike openings extending through the refractory element and positioned about said refractory element to permit anchoring of the metal structure to the absorptive elongated element through said openings as the sole anchoring means for the refractory member, each pluglike opening lying wholly within a single integral part of the hollow element. 7

2. The improvement of claim 1 wherein said openings are positioned along the length of the hollow element on both sides of and substantially adjacent a horizontal centerline of the refractory member.

3. The improvement of claim I wherein said openings are frustoconical shaped.

4. The improvement of claim 2 wherein said openings are staggered with respect to each other so as not to lie in any common vertical plane.

5. A refractory member for protecting a skid pipe having a wear bar mounted thereto comprising an elongated refractory element constructed of two connected integral parts and having a first opening therethrough and a segmented upper surface defining a second opening in cooperation with the first opening so that the elongated refractory element snugly fits over the skid pipe and the second opening cooperates with the wear bar and an interconnected metal mesh solidly embedded within the elongated refractory element and positioned about and adjacent the first opening so as to be substantially adjacent said skid pipe, said elongated refractory element having a plurality of spaced and staggered pluglike openings extending therethrough to permit anchoring of the metal mesh to the skid pipe through said pluglike openings as the sole anchoring means for the protective refractory member, each pluglike opening lying wholly within a single integral part of the hollow element. 

1. In a protective refractory member for protecting heat absorptive elongated elements in a furnace and having two connected integral parts forming a refractory elongated hollow element and an interconnected reticulated metal structure solidly embedded within said hollow element and positioned about and adjacent the hollow portion so as to be substantially adjacent said heat absorptive elongated element, the improvement comprising a plurality of spaced pluglike openings extending through the refractory element and positioned about said refractory element to permit anchoring of the metal structure to the absorptive elongated element through said openings as the sole anchoring means for the refractory member, each pluglike opening lying wholly within a single integral part of the hollow element.
 2. The improvement of claim 1 wherein said openings are positioned along the length of the hollow element on both sides of and substantially adjacent a horizontal centerline of the refractory member.
 3. The improvement of claim 1 wherein said openings are frustoconical shaped.
 4. The improvement of claim 2 wherein said openings are staggered with respect to each other so as not to lie in any common vertical plane.
 5. A refractory member for protecting a skid pipe having a wear bar mounted thereto comprising an elongatEd refractory element constructed of two connected integral parts and having a first opening therethrough and a segmented upper surface defining a second opening in cooperation with the first opening so that the elongated refractory element snugly fits over the skid pipe and the second opening cooperates with the wear bar and an interconnected metal mesh solidly embedded within the elongated refractory element and positioned about and adjacent the first opening so as to be substantially adjacent said skid pipe, said elongated refractory element having a plurality of spaced and staggered pluglike openings extending therethrough to permit anchoring of the metal mesh to the skid pipe through said pluglike openings as the sole anchoring means for the protective refractory member, each pluglike opening lying wholly within a single integral part of the hollow element. 